The present invention relates to a coordinate input apparatus, and more particularly to a so-called touch panel type coordinate input apparatus which has a coordinate input face and by which the coordinates of a position on the coordinate input face touched by a finger or a pen can be inputted.
To date, a touch panel type coordinate input apparatus which is connected to a display device, such as a display, and used has been employed. This type of coordinate input apparatus has a coordinate input face called xe2x80x9ctouch panelxe2x80x9d, supplies coordinates inputted on the coordinate input face to a display device, and superposes and displays letters and/or line drawings formed by inputted coordinates upon an image displayed on the display device.
As this type of coordinate input apparatus, for example, there is one disclosed in Japanese Patent Application Laid-Open No. 9-91094. This coordinate input apparatus comprises a coordinate input face 161 composed of a transparent glass substrate, two scanner lights 160 arranged in corners of the coordinate input face 161, and a reflection array 162 arranged in three sides around the coordinate input face 161 as shown in FIG. 18.
The scanner lights 160 emit approximately parallel lights to the coordinate input face 161. The lights that the scanner lights 160 emit are recursively reflected at the reflection array 162 on the whole area of the coordinate input face 161 and are received by the scanner lights 160. In this state, when coordinates are inputted on the coordinate input face 161 by means of a finger or a pen, the lights that the scanner lights 160 have emitted are shielded on the coordinates and do not reach to the reflection array 162, and no reflection is received at the scanner lights 160. The two scanner lights 160 in the right and the left sides specify straight lines that pass through the inputted coordinates by angles of rotation, respectively, when no reflection is received and detect the coordinates inputted as the point of intersection of both straight lines.
In a meeting or a presentation where this type of coordinate input apparatus is employed, there is an occasion in which writing on a display device simultaneously by a plurality of operators is desired in order to smoothly proceed questions and answers or the like. However, when two operators input, for example, a point P1 (x1, y1) and a point P2 (x2, y2), respectively, through the coordinate input apparatus shown in FIG. 18, one scanner light 160 detects rotation angles xcex8L1, xcex8L2, and the other detects rotation angles xcex8R1, xcex8R2.
At this time the coordinate input apparatus of FIG. 18 cannot determine whether the coordinates inputted are to be decided by combining the rotation angle xcex8L1 and the rotation angle xcex8R1 and the rotation angle xcex8L2 and the rotation angle xcex8R2 or combining the rotation angle xcex8L1 and the rotation angle xcex8R2 and the rotation angle xcex8L2 and the rotation angle xcex8R1. Thus, there is a fear that a point P1xe2x80x2 and a point P2xe2x80x2 as well as the inputted points P1, P2 may become considered as inputted points, thereby impeding writing on the display device by a plurality of operators.
It is an object of the present invention to provide a coordinate input apparatus and a recording medium of a coordinate input apparatus wherein when a plurality of sets of coordinates are inputted, these sets of coordinates can be distinguished for each pointing means and thus inputting by a plurality of operators is possible.
That is, a coordinate input apparatus according to the present invention is characterized in comprising a coordinate input face where coordinates are inputted by a pointing means, at least two angle detection means respectively periodically detecting respective angles formed by straight lines connecting a pointed point pointed by the pointing means on the coordinate input face and reference points on the coordinate input face and a reference line on the coordinate input face, an angle storing means storing the angles detected during an immediately earlier cycle among angles periodically detected, an angle choosing means choosing angles which are most adjacent to the angles stored in the angle storing means among angles detected at this time when the number of angles of this detection time periodically detected by the angle detection means is greater than that of angles of the last time, and a coordinate detection means detecting coordinates inputted by the pointing means based on the angles chosen by the angle choosing means.
By constituting like this, when pointing by a plurality of pointing means is performed on the coordinate input face, the pointed point pointed by the pointing means through which the previous coordinates have been detected can be discriminated and the coordinates thereof can be detected.
According to another aspect of this invention, this invention comprises a coordinate input face where coordinates are inputted by a pointing means, at least two angle detection means respectively periodically detecting respective angles formed by straight lines connecting a pointed point pointed by the pointing means on the coordinate input face and reference points on the coordinate input face and a reference line on the coordinate input face, an angle storing means storing the angles detected during an immediately earlier cycle among angles periodically detected, an angle choosing means choosing angles which are most adjacent to the angles stored in the angle storing means among angles detected at this time when the number of angles of this detection time periodically detected by the angle detection means is greater than that of angles of the last time, an identifier adding means adding a first identifier to the angle chosen by the angle choosing means, and a coordinate detection means detecting coordinates of the pointed point based on the angle detected by the angle detection means, wherein the coordinate detection means detects the coordinates of the pointing means which are continuous with the coordinates which are based on the angles stored in the angle storing means based on the angle to which the identifier adding means has added the first identifier, and the angle storing means stores the angle to which the identifier adding means has added the first identifier.
By constituting like this, when pointing by a plurality of pointing means is performed on the coordinate input face, the pointed point pointed by the pointing means through which the previous coordinates have been detected can be discriminated and while adding the first identifier, the coordinates thereof can be detected. Thus, a stroke drawn by pointed points to which the first identifiers are added can be detected.
According to a recording medium of coordinate input apparatus according to the present invention, a program is stored readable by a central processing unit of a coordinate input apparatus comprising a coordinate input face where coordinates are inputted by a pointing means and at least two angle detection means respectively periodically detecting respective angles formed by straight lines connecting a pointed point pointed by the pointing means on the coordinate input face and reference points on the coordinate input face and a reference line on the coordinate input face, wherein the recording medium stores a program comprising an angle storing step storing the angles detected during an immediately earlier cycle among angles periodically detected, an angle choosing step choosing angles which are most adjacent to the angles stored in the angle storing step among angles detected at this time when the number of angles of this detection time periodically detected is greater than that of angles of the last time, and a coordinate detection step detecting coordinates inputted by the pointing means based on the angles chosen by the angle choosing step.
By constituting like this, when pointing by a plurality of pointing means is performed on the coordinate input face, the pointed point pointed by the pointing means through which the previous coordinates have been detected can be discriminated and the coordinates thereof can be detected. Further, the program can be made software, thereby eliminating the necessity of employing an exclusive constitution for the central processing unit.
According to another aspect of this invention, this invention comprises a program is stored readable by a central processing unit of the coordinate input apparatus comprising a coordinate input face where coordinates are inputted by a pointing means, at least two angle detection means respectively periodically detecting respective angles formed by straight lines connecting a pointed point pointed by the pointing means on the coordinate input face and reference points on the coordinate input face and a reference line on the coordinate input face, and angle storing means storing the angles detected during an immediately earlier cycle among angles periodically detected by the angle detection means, wherein the recording medium stores a program comprising an angle choosing step choosing angles which are most adjacent to the angles stored in the angle storing means among angles detected at this time when the number of angles of this detection time periodically detected is greater than that of angles of the last time, a first identifier adding step adding a first identifier to the angle chosen in the angle choosing step, a coordinate detection step detecting the coordinates of the pointing means which are continuous with the coordinates which are based on the angles stored in the angle storing step based on the angle to which the first identifier has been added in the first identifier adding step, and a substituting and storing step substituting and storing the angle to which the first identifier has been added in the first identifier adding step.
By constituting like this, when pointing by a plurality of pointing means is performed on the coordinate input face, the pointed point pointed by the pointing means through which the previous coordinates have been detected can be discriminated and while adding the first identifier, the coordinates thereof can be detected. Thus, a stroke drawn by pointed points to which the first identifiers are added can be detected. The program can be made software, thereby eliminating the necessity of employing an exclusive constitution for the central processing unit.
Other objects and features of this invention will become understood from the following description with reference to the accompanying drawings.